Backing wheel for belt type polishing machines



v B. F. FOWLER 2,402,131

BACKING WHEEL FOR BELT TYPE POLISHING MACHINES Filed Sept. 14, 1944'nmumnur 1 lllllll :llllllllllll I III! llllIlI|llllllllllllllllllllllllllllllllllllllllllllllllllllllllg ll|||II|'"'""llllllll dim AT T ORNEY8.

Patented June 18, 1946 BACKING WHEEL FOR BELT TYPE POLISHING MACHINESBert F. Fowler, Hinsdale, Ill., assignor to The Studebaker Corporation,South Bend, Ind., a corporation of Delaware Application September 14,1944, Serial No. 553,991

6 Claims.

This invention relates, in general, to polishing or finishing machines,and has particular relation to an improved backing wheel for belt typemachines of this character.

In machines of the class described, an emery belt or other polishing orfinishing belt travels over a backing wheel, and the object to bepolished or finished is ap lied against the emery or other polishing orfinishing surface of the belt along the portion of the belt that isbacked by the backing wheel.

The object to be polished or finished may be, for example, a fender orother body part of an automotive vehicle, or it may be a part which itis desired to make smooth, for example, after a soldering, brazing,welding or the like operation, or any other part to be polished orfinished.

If the circumference of such a backing wheel is too hard or rigid itwill not accommodate itself to irregular surfaces or operate uniformlyupon various uneven surfaces which require polishing or finishing, forexample, convex, concave, and angular surfaces, and various combinationsthereof. On the other hand, if the circumference of the wheel is toosoft, the desired polish or finish is not obtained.

Backing wheels formed of rubber or rubberlike materialhave beenprovided, but they produce a chattering action and otherwise are notsatisfactory. Chatter-marks or other irregular markings are produced onthe surface of an object polished or finished on a belt backed by such awheel, and, as a result, the desired polish or finish is not produced.

One of the main objects of the present invention is to provide animproved backingwheel of the class described which will provide bettercooperation between the polishing or finishing surface of the belt andthe object to be polished or finished, and, as a result, betterpolishing or finishing of the object.

Another object of the invention is to provide a backing wheel which issufliciently soft or yielding to provide the desired accommodation ofthe polishing or finishing surface of the belt to various irregularsurfaces and which will produce uniform operation of the belt uponvarious uneven surfaces, for example, convex, concave, and angularsurfaces, and various combinations thereof; also a, backing wheel havingthe desired soft or yielding properties combined with a circuml'erencewhich will provide and maintain improved contact of the polishing orfinishing surface of. the belt with the surface of the object to bepolished or finished.

Another object of the invention is to provide an improved backing wheelcomprising a relatively yielding body having its circumference coveredwith a coating secured to the circumference of the body and broken intopieces which, in operation of the wheel, will tend to be forcedoutwardly by centrifugal force to provide and maintain improved contactof the polishing or finishing surface of the belt with the object to bepolished or finished; the yielding bod of the wheel and the brokencharacter of the coating at the same time enabling effective and uniformcooperation with all portions of irregular, as well as smooth, surfacesof the object to be polished or full bed.

A other object of the invention is to provide a backing wheel having animproved form of yielding body; more particularly, a yielding bodycomprising a plurality of sections each of which comprises a pluralityof suitable fabric discs stitched together out from the center to adistance short of or spaced inwardly from the circumference of the wheelan amount that will provide the de sired degree of softness or yieldingcharacter along the circumference ofthe wheel.

Another object of the invention is to provide a backing wheel having ayielding body comprising sections composed of fabric discs stitchedtogether to a distance short of or spaced inwardly from thecircumference of the wheel, combined with sections composed of fabricdiscs stitched together out to, or substantially to, the circumferenceof the wheel.

Further objects and advantages of the invention will appear from thefollowing detailed description, taken in connection with theaccompanying drawing which illustrates the manner of constructing andoperating a backing wheel in accordance with the present invention.

In the drawing:

Figure 1 is a more or less simplified side elevational view of apolishing or finishing machine showing a backing wheel embodying thepresent invention employed thereon;

Figure 2 is a perspective view of one form of backing wheel embodyingthe present invention;

Figure 3 is a fragmentary radial section taken substantially on the line3-3 of Figure 2;

Figure 4 is a perspective view of another form of backing wheelembodying the present invention; and

Figure 5 is a fragmentary radial section taken substantially on the line5-5 of Figure 4.

Referring now to the drawing, the polishing or finishing machine shownin more or less simpiified form in Figure l, and which is forillustrative purposes, comprises a main body It on which the backingwheel I l of the Present invention is Journaled for rotation at l3.Guide pulleys l4 and I5 are journaled for rotation at IS and I1, and anidler pulley I8 is journaled for rotation at IS. The pulleys ill, l5 and58 are preferably of crowned form to keep the belt from slipping off.

The backing wheel Ii preferably acts as the driving wheel for thepolishing or finishing belt 20 which is trained about and travels overthe wheel I! and pulleys It, IS, and 58, preferably.

in the direction indicated by the arrow 2|. The wheel II is driven froma motor or other driving means by a belt or other driving connection(not shown). The driving means may be housed within the body it foraccess, for example, through a door 22. The pivoted arm 23 on which theidler pulley i8 is journaled is urged clockwise about its pivot 24 by aspring 25 to maintain proper tension in the belt 20.

The spring 25 is connected, for example, at one end to thebody i0 and,at its other end, to the arm 23 through a flexible element 26 trainedover a sheave 21. A hand lever 23, pivoted to the body it and connectedby a link 29 to the arm 2Z3r is adapted for swinging the arm 23counterclockwise against the tension of the spring 25 in order torelease the tension in the belt 23 for application and removal of thesame. The foregoing details are for illustrative purposes and may varywidely.

The backing wheel ii, shown in Figures 1, 2, and 3, comprises arelatively yielding body composed, for example, of a plurality ofintermediate fabric sections 30 each comprising a plurality of fabricdiscs (such as canvas or the like) and a pair of end sections 3i, one ateach of the opposite ends of the wheel. Each of the end sections 3| alsocomprises a plurality of fabric discs which may also be made of canvasor the like. In the illustrated embodiment of the invention the body ofthe wheel is composed of twelve intermediate sections 30 and the two endsections 3|, but this may, of course, vary.

The fabric discs of each intermediate section 33 are shown as stitchedtogether at 32 out from the center of the wheel to a distance short ofor spaced inwardly from the circumference of the wheel an amount thatwill provide the desired degree of softness or yielding character alongthe circumference of the wheel. The spacing of the stitching 32 from thecircumference. of the wheel will vary according to the size andcharacter of the wheel and the properties desired therein.

The fabric discs of the end sections 3| are shown stitched together at33 out to, or substantially to, the circumference of the body of thewheel II to provide stability at the ends of the wheel. The fabricsections 30 and 3| are provided with coaxial openings 34 for receivingthe mandrel or shaft on which the wheel II is fixed for rotation, andend plates or collars, (not shown) may be provided for clamping thefabric sections 30 and 3| together centrally of the wheel, as well knownin the art. The stitching at 32 and 33 may be spiral stitching as wellknown, or any other suitable stitching.

A fabric wrapping 35 is applied circumferentially about thecircumference of the fabric sections 30 and 3| and its free ends may besecured to the circumference of the body part of the wheel H by suitableglue or adhesive.

A, coating 36, preferably comprising glue or a gelatin-like or glue-likematerial which will adhere to the circumference of the body of the wheelII, is applied to the circumference of the wheel, for example, bypainting it thereon. While the coating material may vary widely withinthe scope of the present invention, one suitable glue for this purposeis marketed by Industrial Lubricant Company of Detroit, Michigan, underthe trade name Grain Lock Cement."

The coating is preferably applied uniformly to provide a relatively thinanduniform coating covering the entire circumference of the wheel ii.The coating 35 will set to a relatively hard and frangible or brittlecondition, and when so set I break the same into numerous relativelysmall pieces 35a, for example, by striking the coating about thecircumference of the wheel with a rod or other suitable implement. Thesmall pieces 36a adhere or are secured to and cover the outercircumference of the wheel it except for the interlacing network ofcracks 38 between the pieces 36. The outer surfaces of the pieces 38conform generally with the circumference of the wheel ii.

In the operation of the machine, the object to be polished, such as afender or other body part of an automotive vehicle or a part which it isdesired to smoothen, polish or finish after soldering. brazing, weldingor the like, or any other part to be polished or finished, is applied orpressed against the outer emery or other finishing or polishing surfaceof the belt 23 along the portion of the belt that is backed by the wheelii. The object is preferably applied to the under part of the wheelbacked part of the belt 2|! to the left of a vertical plane through theaxis of the wheel H as it is viewed in Figure 1, and, so applied, theobject is preferably worked upwardly in the polishing or finishingoperation.

In the polishing or finishing operation the circumference of the backingwheel ii is sufiiciently soft or yielding to provide the desiredconformity to irregular as well as regular surfaces of the object anduniform operation upon various uneven surfaces. At the same time thenumerous pieces 3611 into which the coating 36 is broken are forced ortend, in the operation of. the machine, to be forced outwardly bycentrifugal force to provide and maintain improved contact of thepolishing or finishing surface of the belt 20 with the object tobepolishedor finished. As a result, the chattering of rubber orrubber-like wheels is avoided, and improved smoothening, polishing or'finishing of the object is obtained.

The embodiment of the invention shown in Figures 4 and 5 of the drawingis similar to the embodiment shown in Figures 1, 2, and 3 except thatthe stitching together at 33, of the fabric discs comprising the endsections 3|. instead of extending out to the circumference of the wheelll, terminateswhere the stitching together at 32', of the discscomprises the intermediate sections 30', terminates, i. e., spacedinwardly of the circumference of the wheel.

The wheel shown in Figures 4 and 5 also has fabric end Pieces 40 and 4|,one covering each of its opposite ends. These fabric end coverings 40and ll are turned in marginally at 43a and a beneath the opposite endsof the fabric wrapping 35' which otherwise corresponds with the fabricwrapping 35 of the preceding embodiment of the invention. The coating33' is similar to thecoating 33 of the preceding embodiment of theinvention, and is applied, broken into pieces, and operates in themanner previously set forth.

The embodiments of the invention shown in the drawing are forillustrative purposes only, and it is to be expressly understood thatsaid drawing and the accompanying specification are not to be construedas a definition of the limits or scope of the invention, reference beinghad to the appended claims for that purpose.

I claim:

1. A backing wheel for a polishing or finishing belt having a relativelyyielding'fabric body comprising a plurality of sections each of which iscomposed of a plurality of fabric discs stitched together outwardly fromthe center to a distance short of or spaced inwardly from thecircumference of the wheel an amount that will provide the desireddegree of softness or yielding char- 'said fabric body having itscircumference covered with an outer non-abrasive coating secured to thecircumference of said body and broken into an irregular patch work ofindividual pieces.

2. A backing wheel for a polishing or finishing belt having a relativelyyielding fabric body comprising sections composed of fabric discsstitched together to a distance short of or spaced inwardly from thecircumference of the wheel combined with sections composed of fabricdiscs stitched together substantially to the circumference of the wheel,and said fabric bod having its circumference covered with an outernonabrasive coatingsecured to the circumference of said bodyandtyhrjoken into an irregular patch work of individual pieces.-

ing belt comprising a body composed of a plu rality of sections v eaclicomprising fabric discs' stitched together-'- out to a distance short ofor spaced inwardly from the circumference of the 6 7 ing thecircumference of said body and comprising a gelatin-like or glue-likematerial applied to the circumference of the body of the wheel andallowed to set, said coating being broken in- 36. 3. A backing wheel fora polishing or finishwith sections composed of fabric discs stitchedtogether out to substantially the circumference of the wheel, and acoating covering the circumference of said wheel and broken into pieces.

5. A backing wheel for a polishing or finishing belt comprising a bodycomposed of intermediate sections comprising fabric discs stitchedtogether to a, distance spaced inwardly from the circumference of thewheel, combined with end sections composed of fabric discs stitchedtogether out to substantially the circumference of the wheel, and acoating covering the circumference of said wheel and comprising agelatin-like or glue-lik material applied to the circumference of thewheel and allowed to set, said coating being broken into pieces.

6. A backing wheel for a polishing 0r finishi ing belt comprising afabric body having its circoating, and fabric pieces covering the endsof the wheel and turned in marginally beneath said coating.

BERT F. FOWLER.

